Merge "trace: ipc_logging: Release the debugfs SRCU when reading" (15b8d65f) · Commits · e / devices / android_kernel_fairphone_FP3

kernel/trace/ipc_logging.c

+39 −11

Original line number	Diff line number	Diff line
		@@ -549,6 +549,7 @@ int ipc_log_extract(void ctxt, char buff, int size)
		struct decode_context *dctxt);
		struct ipc_log_context ilctxt = (struct ipc_log_context )ctxt;
		unsigned long flags;
		int ret;

		if (size < MAX_MSG_DECODED_SIZE)
		return -EINVAL;
		@@ -558,6 +559,11 @@ int ipc_log_extract(void ctxt, char buff, int size)
		dctxt.size = size;
		read_lock_irqsave(&context_list_lock_lha1, flags);
		spin_lock(&ilctxt->context_lock_lhb1);
		if (ilctxt->destroyed) {
		ret = -EIO;
		goto done;
		}

		while (dctxt.size >= MAX_MSG_DECODED_SIZE &&
		!is_nd_read_empty(ilctxt)) {
		msg_read(ilctxt, &ectxt);
		@@ -573,11 +579,17 @@ int ipc_log_extract(void ctxt, char buff, int size)
		read_lock_irqsave(&context_list_lock_lha1, flags);
		spin_lock(&ilctxt->context_lock_lhb1);
		}
		if ((size - dctxt.size) == 0)
		ret = size - dctxt.size;
		if (ret == 0) {
		if (!ilctxt->destroyed)
		reinit_completion(&ilctxt->read_avail);
		else
		ret = -EIO;
		}
		done:
		spin_unlock(&ilctxt->context_lock_lhb1);
		read_unlock_irqrestore(&context_list_lock_lha1, flags);
		return size - dctxt.size;
		return ret;
		}
		EXPORT_SYMBOL(ipc_log_extract);

		@@ -835,6 +847,8 @@ void *ipc_log_context_create(int max_num_pages,
		ctxt->nd_read_page = ctxt->first_page;
		ctxt->write_avail = max_num_pages * LOG_PAGE_DATA_SIZE;
		ctxt->header_size = sizeof(struct ipc_log_page_header);
		kref_init(&ctxt->refcount);
		ctxt->destroyed = false;
		create_ctx_debugfs(ctxt, mod_name);

		/* set magic last to signal context init is complete */
		@@ -857,6 +871,21 @@ void *ipc_log_context_create(int max_num_pages,
		}
		EXPORT_SYMBOL(ipc_log_context_create);

		void ipc_log_context_free(struct kref *kref)
		{
		struct ipc_log_context *ilctxt = container_of(kref,
		struct ipc_log_context, refcount);
		struct ipc_log_page *pg = NULL;

		while (!list_empty(&ilctxt->page_list)) {
		pg = get_first_page(ilctxt);
		list_del(&pg->hdr.list);
		kfree(pg);
		}

		kfree(ilctxt);
		}

		/*
		* Destroy debug log context
		*
		@@ -865,25 +894,24 @@ EXPORT_SYMBOL(ipc_log_context_create);
		int ipc_log_context_destroy(void *ctxt)
		{
		struct ipc_log_context ilctxt = (struct ipc_log_context )ctxt;
		struct ipc_log_page *pg = NULL;
		unsigned long flags;

		if (!ilctxt)
		return 0;

		while (!list_empty(&ilctxt->page_list)) {
		pg = get_first_page(ctxt);
		list_del(&pg->hdr.list);
		kfree(pg);
		}
		debugfs_remove_recursive(ilctxt->dent);

		spin_lock(&ilctxt->context_lock_lhb1);
		ilctxt->destroyed = true;
		complete_all(&ilctxt->read_avail);
		spin_unlock(&ilctxt->context_lock_lhb1);

		write_lock_irqsave(&context_list_lock_lha1, flags);
		list_del(&ilctxt->list);
		write_unlock_irqrestore(&context_list_lock_lha1, flags);

		debugfs_remove_recursive(ilctxt->dent);
		ipc_log_context_put(ilctxt);

		kfree(ilctxt);
		return 0;
		}
		EXPORT_SYMBOL(ipc_log_context_destroy);

kernel/trace/ipc_logging_debug.c

+25 −6

Original line number	Diff line number	Diff line
		/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2012-2015, 2017, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -74,23 +74,42 @@ static int debug_log(struct ipc_log_context *ilctxt,
		static ssize_t debug_read_helper(struct file file, char __user buff,
		size_t count, loff_t *ppos, int cont)
		{
		struct ipc_log_context *ilctxt = file->private_data;
		struct ipc_log_context *ilctxt;
		struct dentry *d = file->f_path.dentry;
		char *buffer;
		int bsize;
		int srcu_idx;
		int r;

		r = debugfs_use_file_start(d, &srcu_idx);
		if (!r) {
		ilctxt = file->private_data;
		r = kref_get_unless_zero(&ilctxt->refcount) ? 0 : -EIO;
		}
		debugfs_use_file_finish(srcu_idx);
		if (r)
		return r;

		buffer = kmalloc(count, GFP_KERNEL);
		if (!buffer)
		return -ENOMEM;
		if (!buffer) {
		bsize = -ENOMEM;
		goto done;
		}

		bsize = debug_log(ilctxt, buffer, count, cont);

		if (bsize > 0) {
		if (copy_to_user(buff, buffer, bsize)) {
		bsize = -EFAULT;
		kfree(buffer);
		return -EFAULT;
		goto done;
		}
		*ppos += bsize;
		}
		kfree(buffer);

		done:
		ipc_log_context_put(ilctxt);
		return bsize;
		}

		@@ -127,7 +146,7 @@ static void debug_create(const char *name, mode_t mode,
		struct ipc_log_context *ilctxt,
		const struct file_operations *fops)
		{
		debugfs_create_file(name, mode, dent, ilctxt, fops);
		debugfs_create_file_unsafe(name, mode, dent, ilctxt, fops);
		}

		static void dfunc_string(struct encode_context *ectxt,

kernel/trace/ipc_logging_private.h

+10 −1

Original line number	Diff line number	Diff line
		/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -119,6 +119,8 @@ struct ipc_log_context {
		struct list_head dfunc_info_list;
		spinlock_t context_lock_lhb1;
		struct completion read_avail;
		struct kref refcount;
		bool destroyed;
		};

		struct dfunc_info {
		@@ -147,6 +149,13 @@ enum {
		((x) < TSV_TYPE_MSG_END))
		#define MAX_MSG_DECODED_SIZE (MAX_MSG_SIZE*4)

		void ipc_log_context_free(struct kref *kref);

		static inline void ipc_log_context_put(struct ipc_log_context *ilctxt)
		{
		kref_put(&ilctxt->refcount, ipc_log_context_free);
		}

		#if (defined(CONFIG_DEBUG_FS))
		void check_and_create_debugfs(void);